Gas sensors made of semiconducting metal oxides or of organic or polymer layers as sensitive material for the detection of gases, or certain components of a gas, are known. The signal evaluation is carried out in the corresponding sensor element by measuring the induced changes of the conductivity, the capacity and/or the escape function based on the presence of the gas or select gas components. To improve the sensor function and/or regeneration, gas sensors are usually operated with an additional heating element at elevated temperatures, generally in the temperature range between 150° C. and 500° C. These heating elements may be applied to the substrate but may also be integrated directly into the substrate. Two connections are provided in each case for controlling the sensitive gas sensor element and the heating element, so that the two elements may be controlled independently of each other.
A gas sensor is known from the publication DE 36 07 065 A1, in which a sensing element made of a metal oxide semiconductor material and a heating element is provided. To detect the instantaneous state of the surroundings, the electrical resistance value of the sensing element during a time period is established, during which the sensing element is not heated by the heating element.